Method and system for designing or deploying a communications network which considers frequency dependent effects

ABSTRACT

A computerized model provides a display of a physical environment in which a communications network is or will be installed. The communications network is comprised of several components, each of which are selected by the design engineer and which are represented in the display. Errors in the selection of certain selected components for the communications network are identified by their attributes or frequency characteristics as well as by their interconnection compatibility for a particular design. The effects of changes in frequency on component performance are modeled and the results are displayed to the design engineer. A bill of materials is automatically checked for faults and generated for the design system and provided to the design engineer. For ease of design, the design engineer can cluster several different preferred components into component kits, and then select these component kits for use in the design or deployment process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to the U.S. patent application Ser. Nos.09/352,678 filed Jul. 14, 1999, now U.S. Pat. No. 6,499,006; 09/318,840filed May 26, 1999, now U.S. Pat. No. 6,317,599; 09/318,841 filed May26, 1999; and 09/318,842 filed May 26, 1999, now U.S. Pat. No.5,493,679; and is also related to the concurrently filed applicationshaving U.S. Ser. Nos. 09/632,853, entitled “Method and System forDesigning or Deploying a Communications Network which ConsidersComponent Attributes”; and 09/633,133, entitled “Method and System forDesigning or Deploying a Communications Network which Allows theSimultaneous Selection of Multiple Components”, all of which areassigned to a common assignee, and the subject matter of theseapplications is incorporated herein by reference.

DESCRIPTION BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to engineering and managementsystems for the design of communications networks (both wireless andwired) and, more particularly, to a system and method for managing areal time bill of materials when designing, evaluating or optimizing theperformance and/or costs of a communication system using athree-dimensional (3-D) representation of the environment. The presentinvention provides the design engineer with the ability to (1) groupcomponents together as a single connected or unconnected unit or“component kit” to simplify selection and assembly of hardwarecomponents, (2) have at his or her disposal in the Parts List Libraryperformance parameters for selected components which are associated withthe signal or “frequency” which will pass through the component suchthat electromechanical properties of the components can be considered ona frequency dependent basis automatically by the system, and (3) have athis or her disposal attributes which are associated with specificcomponents in the Parts List Library which, acting in concert withreal-time smart processing, provide the design engineer withnotifications or warnings when he or she has proposed connections,components, or other arrangements which will not operate correctly inthe communications network.

2. Background Description

As wireless communications use increases, radio frequency (RF) coveragewithin buildings and signal penetration into buildings from outsidetransmitting sources has quickly become an important design issue forwireless engineers who must design and deploy cellular telephonesystems, paging systems, or new wireless systems and technologies suchas personal communication networks or wireless local area networks.Designers are frequently requested to determine if a radio transceiverlocation, or base station cell site can provide reliable servicethroughout an entire city, an office, building, arena or campus. Acommon problem for wireless systems is inadequate coverage, or a “deadzone,” in a specific location, such as a conference room. It is nowunderstood that an indoor wireless PBX (private branch exchange) systemor wireless local area network (WLAN) can be rendered useless byinterference from nearby, similar systems. The costs of in-building andmicrocell devices which provide wireless coverage within a 2 kilometerradius are diminishing, and the workload for RF engineers andtechnicians to install these on-premises systems is increasing sharply.Rapid engineering design and deployment methods for microcell andin-building wireless systems are vital for cost-efficient build-out.

Analyzing radio signal coverage penetration and interference is ofcritical importance for a number of reasons. A design engineer mustdetermine if an existing outdoor large scale wireless system, ormacrocell, will provide sufficient coverage throughout a building, orgroup of buildings (i.e., a campus). Alternatively, wireless engineersmust determine whether local area coverage will be adequatelysupplemented by other existing macrocells, or whether indoor wirelesstransceivers, or picocells, must be added. The placement of these cellsis critical from both a cost and performance standpoint. If an indoorwireless system is being planned that interferes with signals from anoutdoor macrocell, the design engineer must predict how muchinterference can be expected and where it will manifest itself withinthe building, or group of buildings. Also, providing a wireless systemthat minimizes equipment infrastructure cost as well as installationcost is of significant economic importance. As in-building and microcellwireless systems proliferate, these issues must be resolved quickly,easily, and inexpensively, in a systematic and repeatable manner.

There are many computer aided design (CAD) products on the market thatcan be used to design the environment used in one's place of business orcampus. WiSE from Lucent Technology, Inc., SignalPro from EDX, PLAnet byMobile Systems International, Inc., and TEMS and TEMS Light fromEricsson are examples of wireless CAD products. In practice, however, apre-existing building or campus is designed only on paper and a databaseof parameters defining the environment does not readily exist. It hasbeen difficult, if not generally impossible, to gather this disparateinformation and manipulate the data for the purposes of planning andimplementation of indoor and outdoor RF wireless communication systems,and each new environment requires tedious manual data formatting inorder to run with computer generated wireless prediction models. Recentresearch efforts by AT&T Laboratories, Brooklyn Polytechnic, andVirginia Tech, are described in papers and technical reports entitled“Radio Propagation Measurements and Prediction Using Three-dimensionalRay Tracing in Urban Environments at 908 MHZ and 1.9 GHz,” (IEEETransactions on Vehicular Technology, VOL. 48, No. 3, May 1999), by S.Kim, B. J. Guarino, Jr., T. M. Willis III, V. Erceg, S. J. Fortune, R.A. Valenzuela, L. W. Thomas, J. Ling, and J. D. Moore, (hereinafter“Radio Propagation”); “Achievable Accuracy of Site-Specific Path-LossPredictions in Residential Environments,” (IEEE Transactions onVehicular Technology, VOL. 48, No. 3, May 1999), by L. Piazzi and H. L.Bertoni; “Measurements and Models for Radio Path Loss and PenetrationLoss In and Around Homes and Trees at 5.85 Ghz,” (IEEE Transactions onCommunications, Vol. 46, No. 11, November 1998), by G. Durgin, T. S.Rappaport, and H. Xu; “Radio Propagation Prediction Techniques andComputer-Aided Channel Modeling for Embedded Wireless Microsystems,”ARPA Annual Report, MPRG Technical Report MPRG-TR-94-12, July 1994, 14pp., Virginia Tech, Blacksburg, by T. S. Rappaport, M. P. Koushik, J. C.Liberti, C. Pendyala, and T. P. Subramanian; “Radio PropagationPrediction Techniques and Computer-Aided Channel Modeling for EmbeddedWireless Microsystems,” MPRG Technical Report MPRG-TR-95-08, July 1995,13 pp., Virginia Tech, Blacksburg, by T. S. Rappaport, M. P. Koushik, C.Carter, and M. Ahmed; “Use of Topographic Maps with Building Informationto Determine Antenna Placements and GPS Satellite Coverage for RadioDetection & Tracking in Urban Environments,” MPRG Technical ReportMPRG-TR-95-14, Sep. 15, 1995, 27 pp., Virginia Tech, Blacksburg, by T.S. Rappaport, M. P. Koushik, M. Ahmed, C. Carter, B. Newhall, and N.Zhang; “Use of Topographic Maps with Building Information to DetermineAntenna Placement for Radio Detection and Tracking in UrbanEnvironments,” MPRG Technical Report MPRG-TR-95-19, November 1995, 184pp., Virginia Tech, Blacksburg, by M. Ahmed, K. Blankenship, C. Carter,P. Koushik, W. Newhall, R. Skidmore, N. Zhang and T. S. Rappaport; “AComprehensive In-Building and Microcellular Wireless CommunicationsSystem Design Tool,” MPRG-TR-97-13, June 1997, 122 pp., Virginia Tech,Blacksburg, by R. R. Skidmore and T. S. Rappaport; “Predicted Path Lossfor Rosslyn, Va.,” MPRG-TR-94-20, Dec. 9, 1994, 19 pp., Virginia Tech,Blacksburg, by S. Sandhu, P. Koushik, and T. S. Rappaport; “PredictedPath Loss for Rosslyn, Va., Second set of predictions for ORD Project onSite Specific Propagation Prediction” MPRG-TR-95-03, Mar. 5, 1995, 51pp., Virginia Tech, Blacksburg, by S. Sandhu, P. Koushik, and T. S.Rappaport. These papers and technical reports are illustrative of thestate of the art in site-specific propagation modeling and show thedifficulty in obtaining databases for city environments, such asRosslyn, Va. While the above papers describe a research comparison ofmeasured vs. predicted signal coverage, the works do not demonstrate asystematic, repeatable and fast methodology for creating anenvironmental database, nor do they report a method for analyzing systemperformance or visualizing and placing various wireless equipmentcomponents that are required to provide signals in the deployment of awireless system in that environment.

While there are many methods available for designing wireless networksthat provide adequate coverage, there is no easy method to ensure thatthe system will be cost effective. For instance, even though thecoverage may be more than adequate, given the chosen wirelessinfrastructure components, the total cost of the system could beprohibitive.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a rapid and automated methodfor generating a bill of materials and cost information in real time, ascomponents for a desired wireless communication system are specifiedand/or replaced by substitute components, while continuously predictingwireless system performance. This automatic method for comparing thecost and performance of competing products or competing designmethodologies, in real time, offers a significant value for wirelessengineers and provides a marked improvement over present day techniques.

It is another object of this invention to provide a communicationsdesign engineer with a software tools which allow him or her to (1)group components together as a single unit or “component kit” tosimplify selection and assembly of hardware components, (2) have at hisor her disposal in the Parts List Library performance parameters forselected components which are associated with the signal or “frequency”which will pass through the component such that electromechanicalproperties of the components can be considered on a frequency dependentbasis either automatically or through the use of a prompt (i.e., thesebeing “frequency dependent characteristics”), and (3) have at his or herdisposal attributes which are associated with specific components in theParts List Library which, acting in concert with real-time smartprocessing, provide the design engineer with notifications or warningswhen he or she has proposed connections, components, or otherarrangements which will not operate correctly in the communicationsnetwork.

According to the invention, a design engineer builds a model of thedesired wireless communications system and specifies each componentnecessary to provide sufficient or optimal system performance. A partslist is maintained, in real time, that contains a definition of eachsystem component and its associated performance and cost parameters.Using this method, the user is able to rapidly change the physicallocation of components within the wireless system in order toinvestigate alternative designs which may use different components, suchas antennas and cables; or use different RF distribution methods and/orvarious types of coaxial or optical splitter systems, etc. Costparameters include both component costs and installation costs. As thesystem is changed through a series of “what-if” scenarios, componentsare replaced with substitute components, cable lengths are modified,antenna systems and base stations are re-positioned to alternatelocations, etc.

Each time a component is added to or deleted from the system model, thebill of materials is automatically updated and component costs, totalcosts, and altered system performance specifications are immediatelyavailable to the design engineer. The designer may choose to swapcomponents for less expensive components. The performancecharacteristics of the system are automatically updated as cost choicesare made to enable the designer to assess the changes in performance andcost at the same time.

The communications design engineer may group several components togetherinto a collection referred to as a “component kit”. Thereafter, he orshe will need only select the “component kit” for inclusion in thecomputerized representation of the physical environment in which thecommunications network will be installed. These “component kits” couldbe custom designed by the design engineer or, alternatively, thesoftware package included in this system could have preselectedcomponents bundled as a “component kit”. The “component kits” allow thedesign engineer to more simply and quickly prepare models of thecommunications network since he or she will be able to selectessentially bundles of communications components at a time. The system;however, will be able to track all the attributes of all the componentsin the selected component kits, including all performance attributes,pricing information, and other physical attributes and maintenanceschedules, such that calculations will automatically consider theperformance criteria, pricing and compatibility for the system designedby the engineer. The component kits may be assembled in the same manneras an actual communication system, including the associated cabling anddistribution system, so that connections between components are alreadyset up when the kit is added into a system; this saves a great deal oftime for the engineer.

Various attributes of components will be associated with specificcomponents in the Parts List Library, such as, for example, whether acomponent is an optical component or one which requires radio signals.As another example, the length of cable in which a signal can propagatewithout unacceptable deterioration may be associated with the cable inthe parts list library. These attributes will be consideredautomatically by the system of this invention such that when a designengineer attempts to model connected components which are not properlyconnectable in the physical world, or when he or she attempts to use toolong a cable length, etc., the system will provide a warning that thesystem being designed will be inoperative or be otherwise flawed. Thiswill allow the designer to immediately recognize errors in design andcorrect for them during the design phase. Without such a facility,errors may not be discovered until installation or use of the system, atwhich point they are far more costly to repair.

Frequency dependent characteristics will also be associated withindividual components in the Parts List Library. This will allow thedesign engineer to automatically consider the effects of signalfrequency on the electrical performance of the designed communicationsnetwork. This feature is especially valuable in light of the fact thatmost of said components are specifically designed to function inmultiple frequency bands, with varying performance with respect tofrequency.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects and advantages will be betterunderstood from the following detailed description of a preferredembodiment of the invention with reference to the drawings, in which:

FIG. 1 shows an example of a simplified layout of a floor plan of abuilding;

FIG. 2 shows effective penetration of Radio Frequency (RF) transmissioninto a building from a macrocell;

FIG. 3 shows a simplified layout of a floor plan of a building includingan outdoor macrocell and an indoor base station;

FIG. 4 shows the layout of FIG. 3, but with a revised base stationdesigned to eliminate interference;

FIG. 5 is a flow diagram of a general method used to design a wirelesscommunication network;

FIG. 6 is a flow diagram of a method used to generate estimates based onfield measurements;

FIG. 7 is a flow diagram of a method used to match best propagationparameters with measured data;

FIG. 8 is a flow diagram of a method for prediction;

FIGS. 9A and 9B together make up a detailed flow diagram of a method togenerate a design of a wireless network and determine its adequacy;

FIG. 10 is a flow diagram showing a method for using watch points duringantenna repositioning or modification;

FIG. 11 shows a simplified layout of a floor plan of a building with abase station and watch points selected;

FIG. 12 shows a dialog box displaying the locations of the selectedwatch points and choices for display information;

FIG. 13 shows a simplified layout of a floor plan of a building with abase station and initial RSSI values for the selected watch points;

FIG. 14 shows a simplified layout of a floor plan of a building with arepositioned base station and changed RSSI values for the selected watchpoints;

FIG. 15 shows a simplified layout of a floor plan of a building with are-engineered base station and changed RSSI values for the selectedwatch points;

FIG. 16 shows a bill of materials summary for a drawing, according thepreferred embodiment of the invention;

FIG. 17 shows a bill of materials summary for a drawing after costs havebeen added to a database, according the preferred embodiment of theinvention;

FIG. 18 is a flow diagram showing the general method of the presentinvention;

FIG. 19 is a flow diagram showing the mechanisms for considering theeffects of various attributes on and frequency characteristics on thecommunications system design, and, as required for notifying thedesigner of any inherent design flaws;

FIG. 20 is a computer display showing the assembly of a “component kit”according to the present invention; and

FIG. 21 is a schematic representation of a floor plan on which thecomponents of a “component kit” have been displayed.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Designof Wireless Communication Systems

Using the present method, it is now possible to assess the RFenvironment in a systematic, organized fashion by quickly viewing signalstrength, or interference levels, or other wireless system performancemeasures. The current embodiment is designed specifically for use withthe SitePlanner™ suite of products available from Wireless ValleyCommunications, Inc. of Blacksburg, Va. However, it will be apparent toone skilled in the art that the method could be practiced with otherproducts either now known or to be developed in the future. (SitePlanneris a trademark of Wireless Valley Communications, Inc.)

Referring now to FIG. 1, there is shown a two-dimensional (2-D)simplified example of a layout of a building floor plan. The method uses3-D computer aided design (CAD) renditions of a building, or acollection of buildings and/or surrounding terrain and foliage. However,for simplicity of illustration a 2-D figure is used. The variousphysical objects within the environment such as external walls 101internal walls 102 and floors 103 are assigned appropriate physical,electrical, and aesthetic values. For example, outside walls 101 may begiven a 10 dB attenuation loss, signals passing through interior walls102 may be assigned 3 dB attenuation loss, and windows 104 may show a 2dB RF penetration loss. In addition to attenuation, the obstructions101, 102 and 103 are assigned other properties including reflectivityand surface roughness.

Estimated partition electrical properties loss values can be extractedfrom extensive propagation measurements already published, which arededuced from field experience, or the partition losses of a particularobject can be measured directly and optimized instantly using thepresent invention combined with those methods described in the copendingapplication Ser. No. 09/221,985, entitled “System for Creating aComputer Model and Measurement Database of a Wireless CommunicationNetwork” filed by T. S. Rappaport and R. R. Skidmore. Once theappropriate physical and electrical parameters are specified, anydesired number of hardware components of RF sources can be placed in the3-D building database, and received signal strengths (RSSI), networkthroughput, bit or frame or packet error rate, network delay, orcarrier-to-interference (C/I), carrier-to-noise (C/N), or chip energy tointerference (Ec/Io) ratios can be plotted directly onto the CADdrawing. The 3-D environment database could be built by a number ofmethods, the preferred method being disclosed in the concurrently filed,copending application Ser. No. 09/318,841. Traffic capacity analysis,frequency planning, co-channel interference analysis can be performed inthe invention along with RF coverage. Other system performance metricsmay be easily incorporated by one skilled in the art through well knownequations.

FIG. 2 depicts effective RF penetration into the building from thedistant macrocell using a close-in virtual macrocell transmitting intothe lossless distributed antenna.

Referring to FIG. 2, there are several windows 104, and even a largeglass foyer 105, on the north wall of the building, so RF penetrationinto this part of the building is quite good, as shown by contour lines108 and 109 for 0 dB and −30 dB, respectively. Even so, interior walls102 cause signal levels in some areas to drop below a minimum useablesignal strength of about −90 dBm, especially in some of the southernrooms, as shown by contour line 110. Consequently, macrocell coveragethere will probably be poor.

Other outdoor macrocells can be modeled in the same way, and theirsignal strength contours plotted, to determine if hand-offs cancompensate for the inadequacies of the macrocell north of the building.If not, then indoor picocells (and their distributed feed systems,antennas, and antenna patterns) can be easily added if necessary, andtheir performance checked using the method, to complement coverageprovided by the macrocells.

The mathematical propagation models used to predict and optimize antennapositioning in a desired environment may include a number of predictivetechniques models, such as those described in the previously cited andfollowing technical reports and papers: “Interactive Coverage Region andSystem Design Simulation for Wireless Communication Systems inMulti-floored Indoor Environments, SMT Plus,” IEEE ICUPC '96Proceedings, by R. R. Skidmore, T. S. Rappaport, and L. Abbott which ishereby incorporated by reference. Some simple models are also brieflydescribed in “SitePlanner 3.16 for Windows 95/98/NT User's Manual”(Wireless Valley Communications, Inc. 1999), hereby incorporated byreference. It would be apparent to one skilled in the art how to applyother system performance models to this method.

Interference, instead of radio signal strength, is the dominantperformance-limiting factor in many situations due to increased wirelesscommunications use. Modeling interference from any source to anestablished or contemplated wireless system is straightforward using themethod. Suppose, for example, that an indoor wireless communicationsystem is assigned a frequency set identical to that of an outdoorwireless system. Although the indoor system may provide sufficient RSSIthroughout its coverage area, interference from the outside system maystill render the indoor wireless system ineffectual in certain parts ofthe building.

Caution must be used, however, when modeling and analyzing interference,since the detrimental effect may also depend upon technologies and/orsignal processing technologies, not just signal power levels. Forexample, a geographic area could have similar narrowband and/or widebandin the 800 MHZ cellular bands, for instance with Advanced Mobile PhoneSystem (AMPS) and Code Division Multiple Access (CDMA) systems, butusers using either technology may be able to coexist if their respectivedemodulation processes reject interference provided by the undesiredsystem. The current embodiment of this invention allows the user toselect the air interface/technology being used by the wireless systembeing designed and automatically adjusts the prediction of interferenceaccordingly.

FIG. 3 shows another rendition of the office building example, but anindoor wireless system 107 has been added. In this example, 800 MHZ AMPStechnology is assigned to both transmitters 106 and 107. Differingwireless standards and technologies such as CDMA and Global SystemMobile (GSM) could have been selected as well. The present inventionuses a database to represent the exact physical air interface standardsof a wide range of technologies and may be easily edited for futureinterface standards. As new technologies are developed, one skilled inthe art could easily modify this invention to include the newtechnologies.

The outdoor wireless system 106 is now interfering with the indoornetwork, and the effect is checked by plotting C/I contours 111 and 112at 0 dB and −30 dB, respectively, for the outdoor system and alsoplotting C/I contours 113 and 114 at 0 dB and −30 dB for the indoorsystem. The 0 dB contour 114 shows where the desired and interferingsignal levels are equal, so the interfering outdoor system's signalpredominates in areas outside this contour. It is obvious that theindoor network is rendered useless throughout many parts of thebuilding. There are a number of possible solutions that may be analyzedby a designer using the present invention.

One solution is to change the indoor system's antenna location orincrease the transmitted power, add more nodes, or select a differentfrequency set. These changes may be made with the simple click of amouse in the method of the invention, so that new channel sets, antennalocations, or alternative antenna systems (such as in-buildingdistributed systems, directional antennas, or leaky feeders) may beevaluated quickly, thereby eliminating guesswork and/or costly on-siteexperimentation with actual hardware. Instead of displaying contours ofcoverage or interference, the present invention also allows the user tospecify fixed or moveable watch points that indicate or displaypredicted performance in extremely rapid fashion at specific points inthe environment.

For example, FIG. 4 illustrates how the same indoor wireless system ofFIG. 3 can provide adequate C/I protection when connected to adistributed indoor antenna system consisting of a two-way splitter 401(3 dB loss+insertion loss) and two 40 foot cable runs 402 to popularcommercial indoor omnidirectional antennas 403. A look at the new 0 dBcontour lines 111 and 215, and −30 dB contour lines 112 a and 216 showthat the coverage inside the building is now adequate; the outdoorsystem 106 no longer causes significant interference in most parts ofthe building. Watch points allow a user to instantly determine spotcoverage or other system performance without having to wait for thecomputation and display of contour plots.

The method allows any type of distributed antenna system to be modeledwithin seconds, while continuously monitoring and analyzing thecomponent and installation cost and resulting link budget, as disclosedbelow, enabling “what-if” designs to be carried out on the fly withminimum guess work and wasted time. It is clear that while an RF systemis shown and described herein, the same concepts may be applied to anycommunications network, with a wide range of distribution methods andcomponents.

In the present embodiment of the invention, the designer identifieslocations in the 3-D environmental database where certain levels ofwireless system performance are desirable or critical. These locations,termed “watch points”, are points in three-dimensional space which thedesigner identifies by visually pointing and/or clicking with a mouse orother input device at the desired location in the 3-D environmentaldatabase. Any number of such watch points may be placed throughout the3-D environment at any location. Watch points may be designated prior toperforming a performance prediction on a given wireless communicationsystem, or may be dynamically created by the user at any time during thecourse of a wireless system performance calculation using the same pointand click technique described above.

Watch points provide graphical and/or textual feedback to a designerregarding the wireless system performance throughout the environment.Depending on the type of visual feedback desired by the designer, watchpoints may take the form of one or more of the following:

A computed number displayed as text that represents received signalstrength (RSSI), signal-to-interference ratio (SIR), signal-to-noiseratio (SNR), frame error rate (FER), bit error rate (BER), or otherwireless system performance metrics;

A small region of solid color whose shade and/or tint varies relative tosome computed wireless system performance metric;

Colored lines linking the watch point location with the location one ormore antennas in the wireless communication system, where the color,thickness, and/or other physical aspect of the connecting line variesrelative to some computed wireless system performance metric anddependent upon whether the forward or reverse wireless system channel isbeing analyzed;

Other form designated by the designer; or

Any combination of the above.

In all cases, the graphical and/or textual representation of each watchpoint is updated in real-time as a result of the instantaneouscomputation of the wireless system performance metrics, which are linkedto the 3-D environmental database, and initiated due to dynamic changesbeing made to the wireless system configuration and/or watch pointposition itself by the user. For example, if the user repositions anantenna using the mouse or other input device, the effect of doing so onthe overall wireless system performance is computed and the results aredisplayed via changes in the appearance of watch points. In addition,numerical values predicted at the watch points are displayed in summaryin a dialog window and written to a text file for later analysis. Thisprocess is described in greater detail in the following sections.

The preferred embodiment of the invention utilizes a 3-D environmentaldatabase containing information relevant to the prediction of wirelesscommunication system performance. This information includes but is notlimited to the location, and the physical and electromagnetic propertiesof obstructions within the 3-D environment, where an obstruction couldbe any physical object or landscape feature within the environment(e.g., walls, doors, windows, buildings, trees, terrain features, etc.),as well as the position and physical and electrical properties ofcommunications hardware to be used or simulated in the environment.

The designer identifies the location and type of all wirelesscommunication system equipment within the 3-D environmental database.This point-and-click process involves the designer selecting the desiredcomponent from a computer parts database and then visually positioning,orienting, and interconnecting various hardware components within the3-D environmental database to form complete wireless communicationsystems. The preferred embodiment of the computer parts database is morefully described below. The resulting interconnected network of RFhardware components (commonly known as a wireless distributed antenna)is preferably assembled using either a drag and drop technique or a pickand place and is graphically displayed overlaid upon the 3-Denvironmental database, and utilizes electromechanical informationavailable for each component via the parts list library in order tofully describe the physical operating characteristics of the wirelesscommunication system (e.g., the system noise figure, antenna radiationcharacteristics, frequencies, etc.). This information is directlyutilized during the prediction of wireless system performance metricsand is discussed later.

The present invention represents a dramatic improvement over prior artby providing the design engineer with instant feedback on wirelesssystem performance metrics as the user alters the physical location ofswitches, routers, repeaters, transducers, couplers, transmitters,receivers, and other components described elsewhere or which would beknown by those of skill in the art, or otherwise modifies the antennasystem. The current embodiment utilizes the concept of watch points toimplement this. Multiple methods of display and a wide range of settingsare available for the designer to use in optimizing antenna placementbased upon wireless system performance values displayed at each watchpoint. One skilled in the art could see how watch points as they areherein described could apply to different implementations as well.Descriptions of the different techniques implemented in the currentinvention are provided in the following sections.

One form of the method allows the designer to dynamically alter theposition, orientation, and/or type of any hardware component utilizedwithin a wireless communication system modeled in a 3-D environmentaldatabase. Using this technique, the designer may identify watch pointsrepresenting critical areas of the 3-D environment that require acertain level of wireless system performance. Such areas could includethe office of the Chief Executive Officer (CEO) of a company, aconference room, a city park, or the office of a surgeon on call. Nextthe designer selects the component of interest within the wirelesssystem. In the present invention, this would be the selection of anantenna or leaky feeder antenna, for example, but one skilled in the artcould see that this could be any physical antenna system component. Oncethe desired hardware component is selected, the designer may beginmaking changes to the state of the component. For example, by moving themouse or other input device cursor, the user could effectively relocatethe selected component to another position in the 3-D environmentaldatabase. This involves the user visually moving the mouse cursor, inreal-time, such that the cursor resides in another portions of the 3-Ddatabase. The present invention recalculates wireless system performancebased upon RSSI, SIR, SNR, FER, BER, or other metric, incorporating theuser's desired change in the position of the selected component.

The calculations combine the electromechanical properties of eachcomponent in the wireless communication system (e.g., noise figure,attenuation loss or amplification, antenna radiation pattern, etc.), theelectromagnetic properties of the 3-D environmental database, and radiowave propagation techniques (detailed later) to provide an estimate ofthe wireless system performance. Calculations are performed at eachwatch point the user has identified, and the graphical display of thewatch point is updated to reflect the result of the calculations.

As the user moves the mouse cursor and effectively repositions theselected component, the overall performance of the wirelesscommunication system may be altered. For example, if the selectedcomponent is an antenna, repositioning the antenna changes theorigination point of radio wave signals being broadcast from theantenna, and can thus dramatically change the reception of adequate RFsignal throughout the environment. Because the graphical display of thewatch points is updated in real-time as the selected component isrepositioned, the designer is provided instant feedback on the revisedwireless system performance, and can make design decisions based uponthe viability of multiple proposed locations and/or wireless systemconfigurations rapidly. While many of the concepts discussed above dealwith wireless networks, one of ordinary skill in the art wouldunderstand that similar features may be implemented for optical,infrared, or baseband networks that use fixed or portable terminals.

In addition to the functionality described above, the designer is freeto add additional watch points in any location within the 3-Denvironmental database at any time during a communication systemperformance prediction. In the current implementation, the designerclicks with the mouse or other input device on the desired location inthe 3-D environmental database to create a new watch point at theselected location that is then updated throughout the remainder of theperformance prediction.

In a similar fashion, the preferred embodiment enables a designer toreorient a selected antenna in real-time with respect to any coordinateaxis while the graphical display of all drawing watch points is updatedto reflect the revised wireless system performance metrics as a resultof the new antenna orientation.

In a similar fashion, a designer may replace an existing hardwarecomponent in the wireless communication system with any componentavailable from the parts list library. In doing so, the changes to thewireless communication system performance as a result of the replacementis reflected in the graphical display of the watch points.

In a similar fashion, a designer may selectively include or exclude anysubset of components within the wireless communication system whileselecting components to involve in the wireless system performancecalculation. For example, a designer could consider the effect ofrepositioning a single antenna, or could consider the combined,composite effect on the watch points as individual antennas arerepositioned within a wireless system network consisting of additional,fixed antenna placements.

In a similar fashion, the designer may choose to allow watch points tobe mobile. That is, instead of positioning a watch point and having thegraphical display of the watch point reflect the changing wirelesssystem performance metric, the designer could instead identify a watchpoint whose position is mobile but whose graphical display remainsconstant. In this scenario, the position of the watch point fluctuatesalong a linear path traced between itself and the current location ofthe mouse cursor until a position within the 3-D database is found atwhich the desired level of wireless system performance metric ismaintained. For example, the designer may create a watch point tomaintain a constant graphical display synonymous with −65 dBm RSSI. Asthe user repositions, reorients, or otherwise alters components withinthe wireless communication system, the watch point alters its positionwithin the 3-D environmental database until a position is found at whicha calculated value of −65 dBm RSSI is determined.

In addition to enabling a designer to reposition, reorient, and/orreplace wireless system components in real-time while visualizing theimpact of such changes at selected watch points within the 3-D database,the user may choose to maintain the current configuration of thewireless communication system and instead create a single, mobile watchpoint. The watch point thus created is dynamically repositioned withinthe 3-D environmental database in real-time by the user by simplyrepositioning the mouse cursor. Positioning the mouse cursor at a givenlocation within the 3-D environmental database is equivalent torepositioning the watch point to match that location. In the presentinvention, this technique is used to allow the mobile watch point torepresent a mobile user in the 3-D environmental database. As in theprevious scenarios, the graphical display of the watch point is updatedin real-time to reflect predicted wireless system performance metrics atthe watch point position. The designer is free to select individualsubsets of wireless system components to involve in the calculations ofwireless system performance. Thus the graphical display of the watchpoint may reflect the performance metrics specific to individualwireless system components or the composite performance metrics due tothe combined effect of multiple selected components. For example, theradiating power of multiple antennas can be combined into a singlemeasure of received signal strength.

The two primary uses of the single mobile watch point technique involvethe analysis of the forward link (or down link) and reverse link (or uplink) of the wireless system. The forward link of a wirelesscommunication system involves the flow of radio signals from the fixedwireless system to the mobile user, while the reverse link of a wirelesscommunication system involves the flow of radio signals from the mobileuser to the fixed wireless system. In the present embodiment, linesegments are drawn between the mobile watch point (which is also themouse cursor) to each antenna the designer has included in the wirelesssystem performance prediction. In addition, the individual or subsets ofantennas identified as having the best wireless system performancecharacteristics are differentiated from the other antennas by alteringthe color and/or other physical appearance of the connector linesbetween the antennas and the watch point. As the designer thenrepositions the mouse cursor, the selected location for the watch pointin the 3-D database, and therefore the effective location of the mobileuser, is adjusted to match that of the mouse cursor. The wireless systemperformance metrics are recalculated at the watch point location for theantenna components selected by the designer, and the graphical displayof the watch point and all connector lines is updated accordingly.

Another improvement over the prior art is the ability to dynamicallymodel the repositioning of leaky feeder antennas and visualize theeffects on wireless system performance. A leaky feeder antenna can bethought of as a cable with many holes regularly spaced along its length.Such a cable would experience a signal loss or emanation at every holeand would thus radiate RF energy along the entire cable length. Leakyfeeder antenna, or lossy coaxial cable as it is sometimes referred, canbe thought of as analogous to a soaker hose where water flows in at thehead of the hose and leaks out through a series of holes. The presentmethod allows the designer to dynamically re-position a portion of theleaky feeder antenna and see in real time the effects on wireless systemperformance at the specified watch points. In the preferred embodiment,distributed antenna systems can be analyzed in terms of thecontributions of individual antennas or collections of antennas taken asa whole, providing “composite” results in the latter case.

Referring to FIG. 5, there is shown the general method of the invention.Before one can run an automated predictive model on a desiredenvironment, a 3-D electronic representation of that environment must becreated in function block 10. The preferred method for generating a 3-Dbuilding or environment database is disclosed in the concurrently filed,copending application Ser. No. 09/318,841. The resulting definitionutilizes a specially formatted vector database format and compriseslines and polygons rather than individual pixels (as in a rasterformat). The arrangement of lines and polygons in the databasecorresponds to obstructions/partitions in the environment. For example,a line in a database could represent a wall, a door, tree, a buildingwall, or some other obstruction/partition in the modeled environment.

From the standpoint of radio wave propagation, each of theobstruction/partition in an environment has several electromagneticproperties. When a radio wave signal intersects a physical surface,several things occur. A certain percentage of the radio wave reflectsoff of the surface and continues along an altered trajectory. A certainpercentage of the radio wave penetrates through or is absorbed by thesurface and continues along its course. A certain percentage of theradio wave is scattered upon striking the surface. The electromagneticproperties given to the obstruction/partitions define this interaction.Each obstruction/partitions has parameters that include an attenuationfactor, surface roughness, and reflectivity. The attenuation factordetermines the amount of power a radio signal loses upon striking agiven obstruction. The reflectivity determines the amount of the radiosignal that is reflected from the obstruction. The surface roughnessprovides information used to determine how much of the radio signal isscattered and/or dissipated upon striking an obstruction of the giventype.

Once this 3-D database of obstruction data has been built, the designengineer performs computer aided design and experimentation of awireless network to be deployed in the modeled environment in functionblock 11, to be described later. Cost and wireless system performancetarget parameters, transmitters, channel lists, placement options andantenna systems are all taken into account by the present invention.

In order to fine tune the experimental predictions, RF measurements maybe optionally taken in function block 12. A preferred method forcollecting RF measurements is disclosed in copending application Ser.No. 09/221,985, supra. If necessary, database parameters that define thepartition/obstruction characteristics may be modified using RFmeasurements as a guide to more accurately represent the modeled 3-Denvironment in function block 13.

The results of the predictive models may be displayed in 3-D overlaidwith the RF measurement data, if any, at any time in function block 14.The design engineer analyzes the differences in the predicted and actualmeasurements in function block 15, and then modifies the RF predictivemodels, if needed, in function block 16. If necessary, the 3-Denvironment database may be modified based on the actual measurements tomore accurately represent the wireless system coverage areas in functionblock 10, and so on iteratively until done. The designer can optionallycontinue with any other step in this process, as desired.

The method of invention may be used in a variety of ways depending onthe goals of the design engineer. FIG. 6 shows a variant on the abovemethod used to generate estimates based on RF measurements. A 3-Ddatabase of the environment must still be generated in function block10. Field measurements are collected in function block 12. The RFmeasurement data are then incorporated into the drawing of theenvironment in function block 61. The design engineer may then generateestimates of power level and location of potential transmitters infunction block 62.

FIG. 7 shows a variant of the method used to achieve optimal predictionaccuracy using RF measured data. Once again, a 3-D database of theenvironment is generated in function block 10. However, beforecollecting field measurements, the design engineer creates a channelplan with “virtual” macrocell locations and power levels in functionblock 71. The field measurements are then collected in function block 12and the “virtual” locations of interfering transmitters can bedetermined in function block 72. The best propagation parameters arethen matched with measured data from the interferers in function block73.

A more detailed description of the method for prediction used in thepresent invention is now described. Referring to FIG. 8, the 3-Denvironment definition is input in function block 801. The first steprequired before predicting the performance of the wireless communicationsystem is to model the wireless system with the 3-D environment.Antennas and types of related components and locations are selected infunction block 802. The desired antennas are chosen from a parts list ofwireless hardware devices that may include a variety of commerciallyavailable devices. Each antenna is placed at a desired location withinthe environment, for instance, in a specific room on a floor of abuilding or on a flag pole in front of a building. A number of othercomponents may be created and placed either within or connected to eachantenna system. These components include, but are not limited to:cables, leaky feeder antennas, splitters, connectors, amplifiers, or anyother user defined component.

FIGS. 9A and 9B show a method for adding antenna systems to a desiredenvironment and generally for running trade-off analyses. First, thedesigner positions and defines outdoor wireless communication systems,if necessary in function block 901. Next, the designer positions anddefines indoor base stations in function block 902. The methods offunction blocks 901 and 902 differ in that the components of indoorwireless system will typically be different than an outdoor wirelesssystem. In both cases, the designer is guided through a series of pulldown menus and point-and-click options to define the location, type ofhardware components and associated performance characteristics of theantenna systems. This data is stored in a database, that also containscost and manufacturing specific information to produce a complete Billof Materials list automatically, to be viewed at any time.

In order to fully describe a communication system in a newly created (orto be modified) wireless or wired system, the designer specifies the airinterface/technology and frequencies associated with network protocol,physical media, or a network such as a wireless system in function block903. For a wireless system, the designer then lays out the full antennasystem for the wireless network in function block 904. Components suchas base stations, cabling, connectors, amplifiers and other items of theantenna system are then selected from a parts list library containinginformation on commercially available hardware components in functionblock 905. Next, the air interface and technology specific parametersare assigned and channel frequencies are customized for the wirelesssystem in function block 906. The channel frequencies are selected frompre-assigned channel clusters and assigned to the wireless system infunction block 907. An antenna system is then configured in functionblock 908, selecting antennas from the parts list library as describedabove. The antennas are placed on the floor plan in function block 909using a point and click of a mouse or other positioning device tovisually place each component in the 3-D database.

At this or any time after a component has been placed on a floor, thedesigner may view a bill of materials in function block 910. Ifnecessary, the parts list may be modified to add or delete components ormodify a component's cost or performance characteristics in functionblock 911. Components may be replaced or swapped for similar componentsfor a quick trade-off analysis of both wireless system performance andoverall cost in function block 912. Components may be added, deleted ormodified to more fully define the wireless communications system infunction block 913. The designer may redisplay the view of theenvironment including the wireless communication system, RF measurementdata, and/or wireless system predicted performance results in a varietyof forms, including 2-D, 3-D wireframe, 3-D wireframe with hidden lines,3-D shaded, 3-D rendered or 3-D photorealistic rendering, at any time infunction block 914.

Typically, a designer will add network system components in succession,where each newly placed system component connects to a previouslypositioned component in the network. For a wireless network, one shouldnote that cables and leaky feeder antennas are defined by a series ofvertices connected by lines representing lengths of cabling as they areplaced on a floor. This is also done for fiber optic and basebandcables. Cables and leaky feeders may also stretch vertically acrossbuilding floors, down the sides of buildings, through elevator shafts,etc., simply by adding a vertex in the cable, changing the verticalheight, and then continuing to place cable in new locations, in functionblock 915. The designer does not need to manipulate a 3-D view of theenvironment and attempt to guide the cables vertically in the 3-D model.The designer may repeat any of the steps in this process, in any order,in the present invention.

Referring again to FIG. 8, once the 3-D environment has been defined andantennas, cables and other objects which are used in network design havebeen selected and located, the wireless system performance predictionmodels may be run in function block 803. A variety of different suchmodels are available and may be used in succession, or alone to generatea sufficient number of “what-if” scenarios for predicting and optimizingof antenna placements and component selections.

Referring to FIG. 10, a method for predictive modeling according theinvention is shown. First, the designer selects the desired wirelesssystem performance prediction model in function block 1001. Preferredmodels are:

Wall/floor Attenuation Factor, Multiple Path Loss Exponent Model,

Wall/floor Attenuation Factor, Single Path Loss Exponent Model,

True Point-to-Point Multiple Path Loss Exponent Model,

True Point-to-Point Single Path Loss Exponent Model,

Distance Dependent Multiple Breakpoint Model,

Distance Dependent Multiple Path Loss Exponent Model,

Distance Dependent Single Path Loss Exponent Model, or

other models as desired by the design engineer.

Also, models for propagation of optical and baseband signals, such asloss, coupling loss, distance-dependent loss, and gains arecontemplated.

The physical and electrical properties of obstructions in the 3-Denvironment are set in function block 1002. Although not all parametersare used for every possible predictive model, one skilled in the artwould understand which parameters are necessary for a selected model.Parameters that may be entered include:

Prediction configuration—RSSI, C/I, and/or C/N (carrier to noise ratio);

Mobile Receiver (RX) Parameters—power, antenna gain, body loss, portableRX noise figure, portable RX height above floor;

Propagation parameters

Partition Attenuation Factors

Floor Attenuation Factors

Path Loss Exponents

Multiple Breakpoints

Reflectivity

Surface Roughness

Antenna Polarization

other parameters as necessary for a given model The designer may savesets of physical, electrical and aesthetic parameters for later re-use.If such a parameter set has been previously saved, the designer may loadthat set in function block 1003, thereby overwriting any parametersalready in selected.

A designer then may select a number of watch points in function block1004 to monitor for wireless system performance. Referring now to FIG.11, there is shown a simplified layout of a floor plan with a basestation 1100. The designer may use a mouse or other positioning deviceto point and click to any number of locations in the floor plan toselect critical areas, or watch points, for monitoring. Here, forinstance, four watch points 1101, 1102, 1103 and 1104 have beenselected.

FIG. 12 shows a display, that lists by location, watch points selectedfor the current prediction. The designer may then select predictions forRSSI, signal to interference ratio (SIR) or signal to noise ratio (SNR).In addition, the designer can see changes in predicted values for eachwatch point in real time as the mouse is moved, or can choose to selectnew antenna positions specifically by clicking on a new location. As thedesigner repositions the mouse cursor, the antenna(s) selected prior toinitiating the prediction are effectually repositioned and/or relocatedaccording to position of the cursor. Once all watch points are selected,the prediction model is run. An alternative embodiment is that watchpoints could be entered and modified on the fly, as the prediction modelis being run, rather than defined only prior to running the model.Another alternative embodiment is that RF values at the watch points areupdated continuously as the mouse is repositioned, without a click beingnecessary.

FIG. 13 shows the floor plan of FIG. 11 with the initial RSSI values foreach watch point 1101, 1102, 1103 and 1104 also shown. The designer maymove the antenna 1100 to a new location and monitor the same watchpoints for coverage. FIG. 14 shows the floor plan of FIGS. 11 and 13with the antenna 1100 moved to a new location 1400. The RSSI values ateach watch point 1101, 1102, 1103, and 1104 are automatically updatedwith values associated with the new location of the antenna.Alternatively, the designer may choose to modify the components withinthe antenna system 1100 for performance or cost reasons. FIG. 15 showsthe floor plan of FIGS. 11 and 13 with a base station 1100 a at the samelocation, but with a higher performance antenna component. The RSSIvalues at each watch point 1101, 1102, 1103, and 1104 are againautomatically updated with values associated with the new wirelesssystem performance parameters.

Referring again to FIG. 10, for RF coverage models, the coverage areasand values are displayed in function block 1005. If so desired, thedesigner modifies the electrical parameters of the obstructions, ormodified components of antenna systems, or modifies antenna systemlocations or orientation, etc. in function block 1006 before runninganother prediction model in function block 1001.

Referring again to FIG. 8, after running a number of models, the designengineer may determine that RF coverage is optimal in decision block804. If so, then depending on the results either a change in thelocation of antenna(s) and components will be desired or possibly just asubstitution of components without a location change. For instance, eventhough the coverage may be more than adequate, the total cost of thewireless system could be prohibitive. A method for optimizing the costsusing a dynamic, real time, bill of materials management system isdisclosed below. Regardless, if the wireless network as currentlymodeled is not deemed optimal, then the method would continue again infunction block 802 to re-select the components.

Once the design is as desired, then the 3-D database holds all ofinformation necessary to procure the necessary components in the Bill ofMaterials. The locations of each component are clearly displayed, and avisual 3-D representation can be viewed as a guide.

Once the communications system design is as desired, the database holdsall of information necessary to procure the necessary components in theBill of Materials. The locations of each component are clearly shown,overlaid with the physical environment, and a visual 3-D representationcan be viewed as a guide.

Generating and Managing a Bill of Materials

As described above, in more detail, the invention uses 3-D computeraided design (CAD) renditions of a building, collection of buildings, orany other such environment that contains information suitable for theprediction of a communications system performance. In an RF system,estimated partition electrical properties can be extracted from radiofrequency measurements already published, and/or specified by thedesigner at any time. Once the appropriate electrical properties arespecified, an unlimited number of RF sources can be placed in the 3-Ddatabase, and received signal strengths intensity (RSSI) orcarrier-to-interference (C/I) ratios can be plotted directly onto theCAD drawing.

The 3-D environment database could be built by a number of methods, thepreferred method being disclosed in the co-pending application Ser. No.09/318,841. Traffic capacity analysis, frequency planning, andCo-channel or adjacent channel interference analysis can be performedconcurrently with the prediction of RSSI, C/I and other wireless systemperformance measures. The antenna system and bill of materials could bebuilt by a number of methods. The preferred method for building theantenna system is described above.

As the designer builds a model of a wireless communications system in aspecified environment, as described above, a full bill of materials ismaintained for every drawing in the environment. That is, each drawingmay contain its own unique set and arrangement of antennas, feed systemsand related components representing a variation in the design of awireless communication system. These components are drawn from a globalparts list library. A number of methods could be used to generate theglobal parts list library, and it would be apparent to one skilled inthe art that varying formats could be used.

In the present invention, the design engineer selects a specificwireless system hardware component from the parts list library usingpull-down menus and displayed dialog windows. The selection criteria fora particular component is wireless system design dependent, butgenerally involves the desirability of a component based upon itselectrical characteristics and potential effect on wireless systemperformance, material cost, and/or installation cost. The presentinvention enables the designer to narrow the focus of componentselection to only those devices contained within the parts list librarythat have the desired characteristics. For example, the design engineermay choose to design a wireless system using components from a specificmanufacturer or set of manufacturers that have a desirable material costand/or electrical characteristics. In doing so, only those devices thatmeet the requested criteria are displayed for selection from dialogwindows in the present invention.

In certain instances, the operating frequency of a wirelesscommunication device may define the electrical characteristics of thedevice. For example, depending on the frequency of the radio signalpassing through an amplifier, the amplifier could have a varying amountof gain. Likewise, the radiating characteristics of antennas differdepending upon the frequency of the radio signal being broadcast.Coaxial cables, connectors, splitters, and other wireless communicationsystem hardware components can also share this property of frequencydependent performance. To accommodate this, the parts list library fromwhich the wireless communication system components are drawn may containfrequency specific information for each component. For example, anamplifier may have its gain specified for both 800 megahertz and 1900megahertz. If this information is available within the parts listlibrary for a component, the present invention automatically utilizesthe frequency varying performance characteristics of the wirelesshardware components within the performance prediction calculations asdescribed below. The frequency of operation, in this case, is obtainedfrom the transmitting source that is providing the radio signal to thewireless hardware component. For example, the base station or repeaterto which the wireless hardware component is attached will have a rangeof frequencies or channels that it operates upon. In this case, thefrequency of operation of the repeater or base station determines thefrequency of the radio signal input into the wireless hardwarecomponent, and the frequency of the radio signal is in turn used todetermine the operating characteristics of the component.

In addition to frequency dependent characteristics, many wirelesscommunication devices have limitations in the manner in which they maybe connected within an antenna system. Certain wireless communicationhardware components are incompatible with other components and may notbe connected together. For example, a fiber optic cable may not attachdirectly to a coaxial cable. Instead, a fiber optic cable would firstconnect to an optical-to-radio frequency converter device, whichconverts the data stream from optical into a radio signal. The coaxialcable would then connect to the output port on the optical-to-radiofrequency converter. In the preferred embodiment of this invention, suchconnectivity restrictions are specified within the parts list library.Thus, the system automatically utilizes the information to prevent thedesigner from interconnecting incompatible components. If the designerattempts to interconnect two incompatible components, the presentinvention provides appropriate warning messages to notify the designerof the error.

Practicing communication network engineers spend tremendous amounts oftime in the design and deployment phase trying to configure properconnections between communication components, such as coaxial cables,optical cables, adapters, antennas, routers, twisted pair cables, leakyfeeder antennas, base stations, base station controllers, amplifiers,attenuators, connector splitters, antenna systems, repeaters, switches,wireless access points, cable boxes, signal splicers, transducers,couplers, splitters, convertors, firewalls, power distribution lines,hubs, and other communication components that are known and understoodby network engineers working in the cable, optical, wireless, networkingand telephone industries. Often, various manufacturers make differentbrands of equipment, that are designed for particular frequency bands,mounting conditions, temperature conditions, and connector types. Forexample, radio frequency (RF) components often have N-connectors or SMAconnectors which may not be interconnected without a proper adapter, andcables must have the proper type of connector in order to properlyinterconnect with other components. Similar connector types and sizes ofconnectors and cables exist for various makes and models of opticalfiber cables, baseband twisted pair and CAT-3 and CAT-5 cables, radiofrequency connectors and cables, and all other components listed above.Furthermore, network designers are often concerned about specific costlimitations, not just of a single device, but a connection ofcomponents, and often the entire system design. What's more, designersmust avoid the improper mismatch of physical attributes, such as theimproper connection of a very heavy component (say a switch box or apower amplifier) to a lightweight mounting fixture or a lightweightcable (say RG-58/u) that is unable to support the weight, temperature,or windload, for example. Also, particular network installations may berequired in environments that have small size, low temperature, low orunusual power, or asthetic requirements, or other particularrequirements that take into account the physical attributes of thecomponents within the network design. One skilled in the art of designand deployment of communication networks is aware of other examples astaught here that typically arise in practical network design anddeployment.

In addition, engineers and technicians often have particular brands ormakes of products that they are required or wish to use in all of theirdesigns. For example, their employer may insist that only certain brandsbe used for all deployment and design. Or, specific model numbers orseries of part numbers may be required in a design. The specificationand proper matching of brands or part numbers for the design of anetwork, which we term “brand choice”, is important for desired resultsin many practical settings. Furthemore, components within acommunications network must have compatable power connections (e.g., anRF distribution system would want to have active components that all usethe same DC voltage, so that multiple power distribution lines would nothave to be run), and components must be properly matched in size,weight, mounting configuration, impedance, and color. Also, designersmust be sure that when they create a network design, components whichthey specify must have comparable maintenance requirements. For example,a designer should not create a network that requires some components tohave constant maintenance, whereas others require only infrequentinspection and tuning (a mismatch in maintenance requirements).

On an even broader scale, it is helpful to have a simple checking methodfor making sure that components are properly designed to match the grossphysical media of the various components. Some network components useand transfer or process optical frequencies (lightwaves), while othersuse radio frequency (RF), such as millimeter, UHF, VHF, or microwavesignals, or baseband signals (VHF and below). Telephone cable, 10 baseT,twisted pair or CAT-5 type signaling is typically baseband, for example.Components which are modeled in the present invention can take inoptical signals and transform them into RF or baseband signals.Similarly, some components take in RF signals and convert them tooptical signals. In the design and deployment of a network, it is vitalthat optical cables be connected directly to optical sources, as opposedto RF or baseband signal sources. Otherwise, a network will not work.Other devices which take input signals that are at RF and produce outputsignals that are at optical frequencies exist. In addition, componentsthat convert or transduce baseband-to-optical, or any other of a numberof combinations of these various gross frequency bands. Physical media,which also may be called modality, may include the cables used in thenetwork design, or may actually describe the processing components thatreceive and transmit at the different gross frequencies.

Components may not have compatible frequency ranges of operation, sothat one part is designed for 800-950 MHz while another is designed for1900-2100 MHz (or 200 nm vs. 300 nm, etc.). Components might haveincompatibilities at the level of specific connectors, so that aconnector on one component could connect with specific connectors on aspecific component, but not with other connectors. Components also mayrequire the connection of other specific components directly to them, orthe presence of specific other components in the antenna system, RFdistribution system, and power supply distribution system, in order tofunction correctly. Conversely, components may not allow the presence ofspecific other components, or of components from some manufacturers, tobe connected directly to them, or even to be present anywhere in thedesign.

All of the above network design considerations are important for adesigner or installer. Also, all of the individual connectors on eachcomponent within a network, as well as each frequency or gross frequencyband used by each component and each connector on each component, needsto be properly tracked and must all be used and properly terminated foran effective network.

The above issues are all addressed in the present invention. Failure tomeet any of the above desired criteria can be considered to be a“fault”, wherein a fault can be detected automatically by the presentinvention in the design or deployment phase. Thus, desired cost, properconnectivity, proper matching of physical attributes, and properconnection of brands, part numbers, or manufacturers, can be readilydetected and properly implemented with ease. Other faults, which followthe same logic as described above would fall within the scope of thsinvention. When proper criteria are met, a fault will not be indicated,and the components within the design are used for computation ofpredictions of network performance. Also, the predictions of performancein a proper design may be compared directly to other designs within thesame environment, as well as with actual measured field data.

Similarly, many wireless communication devices have limitations on thesignal power that may be input into them. For example, an amplifier mayonly function properly if the input signal to the amplifier does notexceed a certain level of power. In the present invention, the power ofa signal supplied to a wireless hardware component is determined to bethe output power of the radio signal leaving the device to whichwireless hardware component is attached within the antenna system.Typically, wireless communication system hardware components have gainsand/or losses such that when a radio signal passes through a component,the radio signal is either amplified or attenuated depending on theoperating characteristics of the component and the frequency of theradio signal. For example, referring to FIG. 4, one of theomnidirectional antennas 403 a is attached to a coaxial cable 402, whichin turn is attached to a transmitter 107 via a splitter 401. If thetransmitter 107 is transmitting with a signal power of 10 dBm, and thetotal loss of the splitter 401 is 4 dB, the input signal power into thecoaxial cable 402 is 6 dBm (the signal power of the transmitter minusthe total loss of the splitter). Similarly, if the total loss of thecable 402 is 2 dB, the input signal power into the antenna 403 a is 4dBm. In the preferred embodiment of the invention, the parts listlibrary contains information regarding the restriction of input signalpower into a component. This allows the system of the present inventionto notify the user of the fault in the design via displayed computerdialog boxes if, given the present configuration of the antenna systemthat has been visually configured and interconnected in the 3-Denvironmental model, that the input signal power into any of thewireless communication system hardware components exceeds the limitsspecified in the parts list library. This immediate feedback isinvaluable to the designer and provides instant recognition of potentialproblems in the configuration of the antenna system.

Similarly, many cable components used in wireless communication systemshave limitations on the total length of any single segment of the cable.For example, a single segment of a specific fiber optic cable may nothave a length exceeding 500 feet in order to maintain the integrity ofthe signal passing through it. In the preferred embodiment, the partslist library will contain such length limitations specified for cablingcomponents. Therefore, if the designer visually configures a segment ofcabling within a wireless communication system such that the totallength of the segment exceeds the maximum cable length specified for thecable component within the parts list library, a warning messageconcerning this fault in the design is displayed to the designer viacomputer generated dialog boxes stating the error. The total length ofthe cable segment is determined from the manner in which the designerhas positioned the cable within the 3-D environmental database. Forexample, referring again to FIG. 4, the length of the coaxial cables 402in the figure is determined on the basis of their physical placement andorientation within the 3-D environmental model. This immediate feedbackprovides invaluable information to a wireless system designer as itprevents potential errors in the wireless communication system design.The maximum length restriction applies to all varieties of cablingcomponents, such as coaxial cables, fiber optic cables, leaky feederantennas, and any other type of wireless hardware cable.

Other limitations of a component may be imposed. The component may needto be within a certain distance from a base station, regardless ofintervening components. A component may need to be a certain heightabove ground level, within a certain distance from a wall (internal orexternal) or from a high-voltage power supply source, or placed in aroom of sufficient size. A component may be illegal for use in a givenlocation, or unavailable from the manufacturer from a given orderinglocation. A component may be too large to fit through existing aperturesproviding access to an indoor location as modeled in the 3-D environmentdatabase above. A component may be too heavy for a floor, or toolightweight for an unattached position. A component may be the wrongsize, color, or shape. A component may be unsuitable for environmentalconditions at a given indoor or outdoor location. Components made byspecific manufacturers may be unsuitable. Components exceeding apercomponent price limit may be unsuitable for a given design; suchlimits may be set for a given type of component e.g. amplifier, antenna,or cable, or may be set for any type of component. One skilled in theart could formulate many other obvious attributes that could also bechecked for faults in a design, in the same manner.

A component may be marginally compatible with a given antenna system andRF distribution system for a given site. Manufacturer-specifiedwarnings, maintained with other component characteristics in thecomponent library, could be delivered appropriately for thesesituations. For example, a manufacturer may specify that a givencomponent may be used at a given power level and perform properly, butthat the engineer should be warned that the component will have areduced operational lifetime, or may perform in a sub-optimal manner, orcause damage to other connected parts, if used at the current inputsignal strength level. One skilled in the art would understand that thisextends to other fault warnings about other marginally suitablecomponents.

The present invention stores these fault warnings and the relevantconditions under which the warnings apply, in the parts list library,and automatically compares the conditions in which a component is placedin an antenna system and RF distribution system in a 3-D model of awireless network site, and if the conditions match, displays a faultwarning dialog window (not shown) to the user containing themanufacturer's warning, which must be dismissed and/or printed beforethe engineer is allowed to proceed with the design.

In the present invention, a cost limitation may be imposed on a givendesign, such that when the engineer places a component which would causethe total cost of the installation, or a portion of the installation(which is tracked in real time as indicated above) to exceed the limit,a fault warning is given. At this point, components which are relativelyexpensive, or inexpensive components appearing repeatedly in the design,might be identified automatically by the system as candidates forreplacement for cheaper parts.

FIG. 19 shows a high level schematic of one mechanism which may be usedto provide the design engineer with information on system performanceand cost information. In block 1800, he selects components which will beused in the computerized model of the physical environment in which thecommunications network is or will be installed. There will be aplurality of different types of components which can be selected (e.g.,splitters, antennas, transmitters, base stations, cables, etc.), andthere will be a plurality of models of the types of components selected(e.g., various types of fiber optic cables, coaxial cables, antennas,etc.). The components will have various attributes 1802 (e.g., type ofsignal carried (i.e., optical or radiowave), maximum propagation length(for cables), etc.), frequency characteristics 1804 (e.g., electricalproperties of a component at two or more frequencies, etc.), and cost1806 information associated with one or more components which areselected in decision block 1800. The selected components will then bedisplayed on the computerized representation of the physical environmentin which the communications system is or will be installed in block1808. The system will automatically determine, based on the attributes1802, whether the components selected can properly work together asintended by the designer or whether the components will satisfy all ofthe demands required of them in the communications system designed bythe designer or any other error which may be present in thecommunications network at decision point 1810. If the communicationsnetwork will not perform properly, the designer will be notified of thefault(s) in the design by a display on the screen, audible warning, orother effective means at block 1812. This will allow the designer to goback and select more suitable components. If there are no faults in thedesign proposed by the designer, one or more prediction models will berun at block 1814, and the results of these calculations will bedisplayed to the designer at block 1816. If changes in frequencyparameters are to be considered in the prediction models, this can bedone at block 1818. If desired, the cost of the componentry used in thecommunications network designed by the designer can be provided in abill of materials at 1820.

In addition, in the preferred embodiment the parts list library containsspecifications for compound components, hereafter referred to as“component kits.” A component kit is a predefined group of selectindividual wireless communication components which may or may not bepartially or wholly interconnected and arranged. Component kits arespecified separate from a 3-D environmental model and are not related tothe physical layout of a facility. For example, a component kit couldconsist of a specific splitter connected with a specific cable, which inturn is connected with a specific antenna. The component kit does notdefine where in the 3-D environmental model the splitter, cable, andantenna are positioned, but simply identifies that they are connected orassembled together. The designer may then select the component kititself in exactly the same manner as any other individual hardwarecomponent and position the complete kit within the 3-D environmentalmodel. Thus, by selecting the kit and positioning it within the 3-Denvironmental model, the designer has automatically selected andpositioned the splitter, cable, and antenna.

An important and novel capability of the present invention is theability to provide communication network performance predictions thatuse the component kits, and to allow such predictions to be comparedwith measured network data. In practice, actual communication networksmay be configured using system components which are configured in aspecific manner, and this specific physical and electricalrepresentation may be done approximately or completely in its entiretyby a component kit. Component kits also contain much more detailedinformation of each component or subsystem within the kit, such asphysical media specifications for proper gross frequencyinterconnection, physical attributes, cost, depreciation and maintenanceschedule information, so that proper interconnections within a kit, andfrom one or more kits to another kit, or from one or more kits to anetwork, may be made without a “fault”, as described herein.Measurements made from actual systems comprised of components that aremodeled either exactly or approximately in a component kit within thepresent invention may be displayed, stored, and compared directly topredictions made by systems designed with the component kit.

Referring to FIG. 20, there is shown a representation of the componentkit computer editing window in the preferred embodiment of theinvention. In FIG. 20, a component kit named “Component Kit #1” 1001 isshown. The component kit represents five individual components that areinterconnected in a certain fashion. A coaxial cable 1002 is connectedwith a splitter 1003. One output connector of the splitter connects toan antenna 1004, while the other output connects to a leaky feederantenna 1005. The leaky feeder antenna then terminates 1006. Thecomputer editor window 1007 graphically portrays the interconnection ofthe various components, and enables the designer to add or removecomponents to the component kit. Once created, the component kit 1001can be selected and positioned within the 3-D environmental model justas any individual component. For example, FIG. 21 shows each of thecomponents 1002-1006 of component kit 1001 positioned in one room of athree dimensional floor plan. The design engineer can then connect othercomponents in the communications network, but also may select othergroups of components or “component kits” for use in the facility definedby the three dimensional floor plan (or multistory facility or campuswide communications network). This enables the designer to quickly placemultiple components in the 3-D environmental model by enabling themultiple components to be selected as placed as a single component.

Once a desired component is selected by pointing and clicking with amouse or other input device (components and component kits may beimported, exported, and exchanged electronically and textually betweenusers in the preferred embodiment of the invention), the design engineermay position the component within the three dimension environmentaldatabase. This process involves the design engineer using the mouse orother input device to visually identify the desired location for thecomponent by clicking (or otherwise identifying) positions within the3-D environmental database. For example, an antenna component could beplaced within a specific room of a building, atop a flag pole on theside of a building, in the center of a park, or any other locationdeemed reasonable by the designer. In similar fashion, hardwarecomponents that span distances (e.g. coaxial cable, fiber optic cable,leaky feeder antenna, or any component having substantial length) areselected and positioned within the 3-D environment by clicking with themouse or other input device to identify the vertices (or end points) ofthe component where each pair of vertices are connected by a timesegment representing a portion of cable. Thus, while certain components,such as point antennas or splitters, for example, require only a singlepoint in the 3-D environment to identify placement in the wirelesscommunication system, other components such as distribution cables ordistribution antennas require the identification of multiple pointsjoined by line segments to identify placement. In the present invention,unique graphic symbols are utilized to represent each wireless systemcomponent and overlaid onto the three-dimensional environmental databaseenabling the designer to visualize the wireless communication system asit would exist in the physical world. As an example of the graphicaldisplay and shown only in two dimensions for convenience, FIG. 4displays a base station 107 connected via two coaxial cables 402 to twoindoor point antennas 403 a and 403 b.

The present embodiment of the invention provides and links informationrelating to wireless system component dependence. Such dependencies mayinclude but are not limited to impedance matching of adjoiningcomponents, maximum run length, proper termination, or some other fault,as described herein. Certain components in the parts list library mayrequire pre-existing components to have been positioned within the 3-Denvironmental database before they themselves may be selected and addedto the wireless system. For example, a splitter or other device designedto interconnect two or more independent components may require that anexisting component be present in the three dimensional database for thesplitter to be connected with. In the previous embodiment of theinvention, if the designer chooses to place a hardware component withinthe 3-D environmental database, and the desired component is dependentupon some other device currently placed in the 3-D database, thedesigner is prompted through a selection window to identify thedependent component and the selected component is positionedaccordingly. In the previous example of the splitter component, if thedesigner chooses to connect the splitter onto the end of an existingcable component by identifying the cable component with the mouse orother input device, the position of the splitter within thethree-dimensional database is automatically assigned to be the end ofthe identified cable. In this way the invention helps prevent the userfrom creating faulty designs. Wireless system components that do nothave such dependencies (e.g., base station transceivers) may be freelypositioned anywhere within the 3-D environmental database that is deemedsuitable by the designer. As this description is specific to oneparticular implementation, one skilled in the art could see howdifferent implementations could be developed and practiced within thescope of this invention.

In the preferred embodiment of the invention, if the wirelesscommunication hardware components have information specified within theparts list library detailing restrictions on, for example, maximum inputsignal power, maximum length, or connectivity restrictions, the presentinvention will notify the designer immediately if any of theserestrictions or limitations are exceeded during the course of thedesign. This notification of a potential fault occurs via computergenerated dialog boxes containing textual warning messages detailing therestriction or limitation being exceeded with the present configurationof the wireless communication system within the 3-D environmental model.

Using the preferred embodiment of the invention, a designer can modeland represent, visually as well as mathematically, complex wirelesscommunication systems involving any number of individual hardwarecomponents selected from the parts list library, interconnected with andlinked to one another to form complete antenna systems. As eachcomponent has associated characteristics regarding electrical properties(e.g. gain, noise figure, attenuation) and cost, the addition, removal,or change of any component directly impacts both the performance of thewireless system and the overall system cost. With the preferredembodiment of the invention, this information is updated in real-time asthe designer makes changes to the wireless system. If a wirelesscommunication system includes a specific hardware component, the presentinvention retrieves the associated electromechanical characteristics andother pertinent information from the parts list library entry that hasbeen specified for the component. This information is stored in adatabase and is then used to quantify the effect that the component hason various aspects of wireless system design parameters or performance.For example, if the parts list library information for a specific cableindicates that the attenuation loss of the cable is 3.5 dB per 100meters, and the designer has added a 200 meter segment of the cable tothe wireless communication system, the present invention combines theinformation regarding the placement and length of the cable in the 3-Denvironmental database with the attenuation loss information from theparts list library to determine a total attenuation loss of 7 dB for thecable. Furthermore, the noise figure and other related qualities of thecable is also computed based upon well known communication theory. Ifthe designer then adds an amplifier to the wireless system and connectsit onto the end of the cable as described above, the invention retrievesinformation regarding the amplifier from the parts list library todetermine overall gain of the wireless distribution system. If, forinstance, the selected amplifier has an associated gain of 10 dB andsome specified noise figure, the present invention combines thecharacteristics of the interconnected cable and amplifier to determine atotal gain of 3 dB for the combined components, and a new system noisefigure. If the designer edits or alters component information in theparts list library, this is automatically reflected in the wirelesssystem performance prediction. For example, if the amplifier in theexample above has the gain associated with it edited in the parts listlibrary and changed from 10 dB to 15 dB, the combined systemcharacteristics, which may include but are not limited to system gainand system noise figure, of the cable and amplifier from the example areautomatically recalculated, resulting in an overall gain of 8 dB insteadof 3 dB. Similarly if the cable is repositioned such that its overalllength is altered or replaced with a different component from the partslist library, the effect of doing so is automatically recalculated anreflected in all future operations.

As mentioned previously, the Parts List Library preferably containsinformation regarding the frequency dependent nature of a wirelesssystem component, the operating characteristics of the componentutilized during the calculation of gains, losses, noise figure, or anyother qualities that utilize the frequency of the input signal into thecomponent to determine the specific set of operating characteristics forthe component. If the component does not have a set of parametersdefined for the desired operating frequency, the present inventionsearches for and uses the set of operating parameters specified for thefrequency closest to the actual frequency of the input signal. This is avery powerful feature of the present invention as it enables a designerto select components for use in a wireless communication system withoutthe need to worry about the operating parameters of the componentrelative to the operating frequency of the wireless communicationsystem. The present invention automatically uses the best set offrequency dependent parameters specified for each wireless hardwarecomponent based on the frequency of the input signal to the component.

The Parts List Library, or component library, of the present inventionalso contains information regarding operating characteristics of acomponent which depend on some combination of the frequency of the inputsignal to the component, the connector on the component to which theinput is applied or through which output is passed, and the direction ofthe signal, i.e., forward link from the base station to the mobilereceiver or reverse link back to the base station from the mobilereceiver. The preferred embodiment specifies a coupling loss thatapplies to a particular component, for a particular frequency range andmodality, for a particular connector on the component, for a particulardirectionality of signal (i.e., forward link or reverse link). Adifferent coupling loss is specified explicitly (or may be derivedautomatically) for each combination of connector, supported frequencyband (of which a given component may have many), and directionality.These values are preferably applied automatically in real time to theaforementioned system performance predictions, according to the activefrequency of the signal arriving at and/or leaving a component, theconnector on which the modeled signal arrives at and/or leaves thecomponent, and whether the forward link or reverse link performance isbeing evaluated. One skilled in the art could implement additionalspecifications dependent on combinations of the frequency, connector,directionality, or other aspects of the signal applied to a component.

Although the given example is in terms of simple gains and losses of theindividual wireless components, one skilled in the art could apply thissame method to any other electrical, electromechanical financial,aesthetic or other quality associated with components in the parts listlibrary and the overall system in a similar fashion.

A preferred Parts List Library is designed to be generic and applicableto any type of wireless communication system component or wirelesscommunication system design methodology. There are eight basiccategories of components in the preferred parts list library utilized inthe preferred embodiment, although more categories could be added, asdesired:

1. Amplifiers/Attenuators—generally speaking, devices that either boostor decrease the strength of radio wave signals;

2. Connectors/Splitters—generally speaking, devices that connect one ormore components to one or more additional components;

3. Cables—various types of cabling (e.g., fiber optic cable, coaxialcable, twisted pair cable, etc);

4. Manufacturer-Specified Point Antennas—any antenna that ismanufactured and whose manufacturer has supplied information with regardto the radiation pattern of the antenna. The radiation pattern of anantenna describes the manner in which radio signals are radiated by theantenna. Antenna manufacturers supply radiation pattern informationregarding their antennas so that wireless system designers can maximizethe effectiveness of antenna deployments;

5. Generic Point Antennas—any generic or idealistic antenna (that is, anantenna that may not be physically realizable or has a generic radiationpattern);

6. Leaky Feeder Cabling/Antennas—a type of antenna that takes the formof a specialized coaxial cable;

7. Base Station/Repeater—the controlling portion of the wirelesscommunication system. The base station manages all communication takingplace in the wireless network;

8. Component kit-one or more individual components interconnected orgrouped interconnected together to form a compound component (thispreferably being done within the discretion of the design engineer byselecting amongst all or some of the components in the Parts ListLibrary to define one or more component kits made of selectedcomponents). The component kit is referenced as a single hardwarecomponent and enables the designer to quickly add and manipulatemultiple wireless hardware components. It preferably has no directlyassigned electromechanical properties defined in the Parts List Library;however, the individual hardware components contained within thecomponent kit retain all electromechanical properties assigned to themwithin the Parts List Library; and

9. Other—Any component that does not belong in one of the abovecategories.

Each component has a variety of associated values. These include, butare not limited to:

Manufacturer Name;

Manufacturer Part Number;

User-supplied Description;

Frequency range at which part has been tested;

Attenuation/Amplification;

Number of Connections;

Physical Cost (material cost of component);

Installation Cost;

Antenna Radiation Pattern;

Maximum input signal power;

Maximum length (for cables);

Modality of component type (e.g., optical, radio signal, etc.)

Note that many or all of the associated values listed above could varydepending on the frequency of the input signal to the component. Theymay also depend on the combination of input signal frequency, connectoron the component to which the signal is applied or via which the signalexits the component, and whether the signal is a forward link signaloriginating at the base station, or reverse link signal originating froma user of the system. The parts list library utilized in the preferredembodiment of the invention allows the amplification/attenuation,radiation pattern, and maximum input signal power to be identified forspecific frequencies of frequency ranges for each wireless hardwarecomponent. The coupling loss varies by frequency, connector, anddirection of signal (forward or reverse link), in the preferredembodiment.

Base stations and repeater components have a number of additionalparameters associated with them, including, but not limited to:

Technology/Air Interface—identifies the wireless technology employed bythe base station (e.g., AMPS (“analog cellular”), IS-136 (“digitalcellular”), IEEE 802.11 (“wireless LAN”), etc.);

Frequency/Channel Assignments-identifies the radio frequencies/channelsthis base station can utilize; and

Transmit Power—the amount of power the base station is broadcasting.

An excerpt from the preferred embodiment of a parts list is shown below.

<ComponentSpec> <databaseKey>5110</databaseKey><name><![CDATA(Ultraflexible Series Cable]]></name> <type>CABLE</type><manufacturer><![CDATA[Bob's Cables and Connectors,Inc.]]></manufacturer> <partNumber><![CDATA[Model 21-A]]></partNumber><purchaseCost>0</purchaseCost> <installationCost>0</installationCost><maximumLength>none</maximumLength><fileDescriptor><![CDATA[N/A]]></fileDescriptor><otherInfo><![CDATA[N/A]]></otherInfo><connectorCount>2</connectorCount> <bandList> <BAND><modality>R</modality> <minFreq>4e+008</minFreq><maxFreq>4e+008</maxFreq> <inputSignalMaxFwd>none</inputSignalMaxFwd><inputSignalMaxRev>none</inputSignalMaxRev><outputSignalMaxFwd>none</outputSignalMaxFwd><outputSignalMaxRev>none</outputSignalMaxRev><insertionLoss>7.42</insertionLoss> <associatedConnector><number>0</number> <couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector><associatedConnector> <number>1</number><couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector> </BAND><BAND> <modality>R</modality> <minFreq>4.5e+008</minFreq><maxFreq>4.5e+008</maxFreq> <inputSignalMaxFwd>none</inputSignalMaxFwd><inputSignalMaxRev>none</inputSignalMaxRev><outputSignalMaxFwd>none</outputSignalMaxFwd><outputSignalMaxRev>none</outputSignalMaxRev><insertionLoss>7.87</insertionLoss> <associatedConnector><number>0</number> <couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector><associatedConnector> <number>1</number><couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector> </BAND><BAND> <modality>R</modality> <minFreq>7e+008</minFreq><maxFreq>7e+008</maxFreq> <inputSignalMaxFwd>none</inputSignalMaxFwd><inputSignalMaxRev>none</inputSignalMaxRev><outputSignalMaxFwd>none</outputSignalMaxFwd><outputSignalMaxRev>none</outputSignalMaxRev><insertionLoss>10</insertionLoss> <associatedConnector><number>0</number> <couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector><associatedConnector> <number>1</number><couplingLossFwd>0</couplingLossFwd><couplingLossRev>0</couplingLossRev> </associatedConnector> </BAND></bandList> </ComponentSpec>

This excerpt from the parts list of the present invention is thecomplete specification of a single component. The excerpt is in XMLformat, and each element of the specification is labeled with XML tags.The <ComponentSpec> tag begins the component, the <databaseKey> tagindicates the internal database key used to index the part, and the</databaseKey> ends the value for the internal database key. Similarly,the specifications include the manufacturer identified by<manufacturer>, the part name identified by <name>, and so on. There isalso a list of frequency bands, marked off by a <bandList> tag. Eachband, demarcated by a <BAND> tag, contains specifications which applyonly when the signal applied to the component is closest to theparticular band. For a band, the modality (e.g. optical, RF, baseband,CAT-5) is indicated with a <modality> tag, and symbolized by ‘R’ for RF,‘O’ for optical, etc. The minimum and maximum frequency that bound theband are marked by <minFreq> and <maxFreq> tags; the signal maxima forinput and output, forward and reverse link, respectively, for the bandare also defined, as is the insertion loss for the band. Finally, a listof connectors supported by the band in question appears, marked by an<associatedConnector> tag. Each set of specifications for an associatedconnector include the connector number as an identifier, and a separatecoupling loss for the forward link and for the reverse link, identifiedby the <connectorNumber>, <couplingLossFwd>, and <couplingLossRev> tags.

Thus the present invention defines specifications dependent on thefrequency alone; dependent on the frequency and the component'sconnector; and dependent on the frequency, the connector, and the linkdirection, whether forward or reverse.

The parts list can be easily modified by a design engineer as newcomponents are placed on the market, removed from the market orre-priced. The ability to maintain a unique equipment list for eachdrawing enables the designer to carry out rapid design analyses tocompare and contrast the performance and cost of different vendorcomponents. The impact of utilizing a specific component in terms ofboth cost and wireless communication system performance can be seenimmediately using the present invention. Information that can be trackedwith the bill of materials includes the manufacturer and part number,physical and installation cost, RF loss characteristics, connections,and the frequencies for which the component is valid. In addition, arich set of customization features is utilized to enable the designer totailor the parts list library to suit the needs of the targetapplication. Moreover, as components with associated length data, suchas cables or leaky feeder antennas, are created, stretched, moved ormodified, their associated costs and impact on wireless systemperformance are automatically updated in the bill of materials toaccount for the change in length. Furthermore, the parts list is storedas an integral part of the drawing database, allowing the user to recalland archive a system design and all of its particulars. In addition, thewireless communication system performance may be recalculatedimmediately, using either a standard link budget equation, noise figureequation, or some other metric such as bit error rate or networkthroughput. This recalculation uses the specific, perhaps frequencyspecific electrical specifications of each component in the system,which are also stored in the bill of materials.

Referring again to the drawings, and more particularly to FIG. 16, thereis shown an example of a bill of materials summary for a drawing. Adescription of the base station “MACROCELL” 1610 is shown to identifythe antenna system for which the summary is shown. The first component1611 is a PCN Panel 1710-1990 92 Deg 9.00 dB Gain point antennamanufactured by Allen Telecom. One should note that the component cost1612, sub-total cost 1613 and total system cost 1614 is $0.00. Thisshows that the designer has not yet updated the parts list library withcurrent costs. When the list has been updated, the summary willautomatically show component costs as well as sub-totals and totals forall base stations and components in the drawing.

FIG. 17 show a bill of materials where costs have been entered into theparts list database. Another component 1720 has been added to the“MACROCELL” base station, also. The costs of each component 1612 a and1721 are now shown. Sub-total 1613 a and Total costs 1614 a are alsoshown.

Referring now to FIG. 18, the general method of the invention is shown.As previously described, first the designer must create a databasedefining the desired environment in function block 180. A preferredmethod is disclosed in the co-pending application Ser. No. 09/318,841. Adatabase of components is then developed in function block 181. In thecase of wireless communication networks, a preferred method is describedabove. The creation of these components will automatically generate aparts list categorized by base station and antenna system. A bill ofmaterials may be displayed at any time in function block 182.

In order to optimize the design of the wireless communications systemand ensure adequate antenna coverage, the designer runs a series ofprediction models and optimization techniques in function block 183. Apreferred method for running predictions is described above. This methodallows the designer to see, in real-time, changes in coverage,generally, and for specifically chosen watch points, as antennas arerepositioned or reoriented. The designer may choose to add, delete orsubstitute components in function block 184 and then re-run the modelsagain in function block 183. Each time the designer makes a modificationin the system to improve performance, the bill of materials isautomatically updated. The designer may run the prediction models infunction block 183, and determine if the wireless system, as designed,is adequate in terms of performance and cost. If not, the designer canchoose to modify components using cost or component performanceconsiderations. Performance parameters may be entered to enable thedesigner to choose substitute components from a list that contains onlythose components that would not degrade the performance of the overallsystem. Note that in the preferred embodiment, the prediction or systemperformance models are recomputed upon user demand, but that it would beapparent to one skilled in the art to also have models recomputedinstantly (“on-the-fly”) as new components are added or subtracted fromthe bill of materials.

The integration of the bill of materials and component performancespecifications is key to providing a quick and efficient method todesign high performance wireless communication networks that are withinbudget. In addition to individual component physical and installationcosts, a collection of components that may be interconnected or possiblyused within a common network may also be specified. Such components froma component kit may be used in a design, and also may be considered forphysical and installation cost. Moreover, within a bill of materialscontaining a list of network components, there may also be a tabulation,computation and storage of other important cost information for some ofthe components, such as cost depreciation values, or schedules fordepreciation of particular components or groups of components. Suchinformation may be available for only certain components within anetwork or within a parts list provided by a particular manufacturer. Inaddition, maintenance schedule information, which specifies theparticular period or dates during which routine maintenance is required,may be included within the description of components within a bill ofmaterials, to help the maintenance staff to properly maintain thedesigned network.

While the invention has been described in terms of its preferredembodiments, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theappended claims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is as follows:
 1. A method for designing ordeploying a communications network, comprising the steps of: providing acomputerized model which represents a physical environment in which acommunications network is or will be installed, said computerized modelproviding a display of at least a portion of said physical environment;providing performance attributes for a plurality of system componentswhich may be used in said physical environment, a number of said systemcomponents having associated with them frequency dependentcharacteristics; selecting specific components from said plurality ofsystem components for use in said computerized model; representing saidselected specific components in said display; running prediction modelsusing the computerized model and said performance attributes to predictperformance characteristics of a communications network comprised ofsaid selected specific components, said prediction models utilizing saidfrequency dependent characteristics in calculations which predict saidperformance characteristics of said communications network.
 2. Themethod of claim 1 wherein said frequency dependent characteristicsdefine electrical properties of said system components at at least twodifferent frequencies.
 3. The method of claim 1 further comprising thestep of generating a bill of materials containing cost information forsaid selected specific components utilized in said communicationsnetwork.
 4. The method of claim 3 wherein said cost informationcomprises a maintenance schedule for selected specific components. 5.The method of claim 1 wherein said display is three dimensional.
 6. Themethod of claim 1 wherein said system components allow convertingbetween radio frequency and optical frequency.
 7. The method of claim 1wherein said system components allow converting between opticalfrequency and baseband frequency.
 8. The method of claim 1 wherein saidsystem components allow converting between radio frequency and basebandfrequency.
 9. The method of claim 1 further comprising the step ofidentifying errors in physical media connections for two or morespecific components selected in said selecting step.
 10. An apparatusfor designing or deploying a communications network, comprising: a meansfor providing (I) a computerized model which represents a physicalenvironment in which a communications network is or will be installed,said computerized model providing a display of at least a portion ofsaid physical environment, and (II) performance attributes for aplurality of system components which may be used in said physicalenvironment, a number of said system components having associated withthem frequency dependent characteristics; a means for selecting specificcomponents from said plurality of system components for use in saidcomputerized model; a means for representing said selected specificcomponents in said display; and a means for running prediction modelsusing the computerized model and said performance attributes to predictperformance characteristics of a communications network comprised ofsaid selected specific components, said prediction models utilizing saidfrequency dependent characteristics in calculations which predict saidperformance characteristics of said communications network.
 11. Theapparatus of claim 10 further comprising a means for generating a billof materials containing cost information for said selected specificcomponents utilized in said communications network.
 12. The apparatus ofclaim 11 wherein said cost information comprises a maintenance schedulefor selected specific components.
 13. The apparatus of claim 10 whereinsaid display is three dimensional.
 14. The apparatus of claim 10 furthercomprising a means for identifying errors in physical media connectionsfor two or more selected specific components.